The repayment on a loan was ?81,000. If the loan was for 2 years and 9 months at 9% interest a year, how much was the principal?
 

We use the formula:  
A=P(1+r/100)^n  
where   
A=future value
P=present value  
r=rate of interest
n=time period.[2 years and 9 months=(2*12)+9=33 months

=33/12=2.75 years]

81,000=P*(1.09)^2.75

P=81,000*1.26742675

=81,000/1.26742675

=63909.02(Approx)